Straight bar knitting machines



April 16, 1968 E. srARr ETAL 3,371,822

STRAIGHT BAH KNITTING MACHINES Filed Oct. 14, 1965 5 Sheets-Sheet l April 16, 1968 E, START ETAL 3,377,82

STRAIGHT BAR KNITTING MACHINES Filed Oct 14, 1965 5 Sheets-Sheet 2 April 16, 1968 E. START ETAL 3,377,822

STRAIGHT BAR KNITTING MACHINES Filed Oct. 14, 1965 s sheets-sheet s April 16, 1968 E. START ETAL. 3,377,822

STRAIGHT BAR KNITTING MACHINES Filed oct. 14. 1965 5 sheets-sheet 4 April 16, 1968 E. START :a1-Al. 3,377,822

STRAIGHT BAR KNITTING MACHINES Filed Oct. 14, 1965 5 Sheets-Sheet 5 United States Patent O ABSTRACT @E THE DISCLSURE In a straight bar knitting machine having frame and machine needles and wherein yarn is fed to the framer needles and on to sinkers Which later relinquish the yarn to the machine needles, with means for automatically changing between plain and rib fabric according to U.S. Patent No. 3,050,967, the improvement of the machine needles being latch needles and the machine having a bar of bent-over-catch-carrying points which are operatively connected to the machine needle advancing mechanism so as to be advanced and retracted thereby and which are also advanced and retracted by cam means relative to the machine needles, and which points have opposite sideways movements under control of solenoid or electro-magnetic clutch and electric switch means to releasably engage the catches with the needle latches for the catches to open the latches in the retraction of the points.

This invention is for improvements in or relating to straight bar knitting machines of the Cottons patent or other similar type and having machine latch needles.

The invention is particularly concerned with this type of machine as modified according to U.S. Patent No. 3,050,967 to be capable of automatically changing between the production of plain and rib fabric, except that instead of the spaced machine needles being bearded needles as in said patent, they are latch needles which as is well known in the art have certain advantages as regards yarn and loop control.

In the use of latch needles, the latches are normally opened and closed by the reciprocatory motion of the needles relative to yarn or loops at diferent sides of the latches, and it is also well known that in instances where the latches are not open when required, for some reason, it is necessary to provide mechanical means for opening the latches.

However since latch needles are usually employed in circular and dat bed knitting machines it is suliicient in these machines simply to traverse with the thread carrier a latch opening brush, but in straight bar machines having two bars of needles the yarn is fed to the frame needles and onto advanced sinkers which later relinquish their yarn to the machine needles at a later stage, and therefore when the thread carrier traverses, the machine needles are covered over by the advanced sinkers, so that a latch opening brush carried by the thread carrier would not engage the machine needles. In the instance of the machine according to said patent and as modified by having machine latch needles, and when the machine needles relinquish their loops to the frame needles for plain knitting to be produced, the machine needle latches are closed by the loops riding off the machine needles, but when subsequently changing from plain to rib fabric, it is necessary for the machine needle latches to be open to receive the new yarn.

An object of the invention is to provide latch opening means of such improved construction as to be satisfactorily employed for opening latches of .machine needles in a straight bar knitting machine.

The invention provides a straight bar knitting machine ICC having machine latch needles and latch opening means comprising a bar of points having their free ends in the form of catches, means for advancing the bar of points to carry the catches to locations at a side 0f the latch ends of the machine needles and for retracting the bar of points, and means for displacing the bar of points in one sideways direction when advanced to engage their catch ends under the needle latches and in the reverse sideways direction following retraction, the arrangement being such that the needle latches are opened by the catches of the points in the latters retraction. Conveniently to provide the catches on the points the pointed ends are bent over at right angles to the stems of the points. Conveniently also the bar of points is operatively connected to mechanism for advancing the machine needles.

More specifically the bar of points is advanced and retracted by cam operated mechanism, an electric switch is operated at the end of the advance motion, an electromagnetic device is energized by operation of the switch to eifect the one sideways displacement of the bar of points, and when the bar of points is retracted, a second electric switch is operated which releases the electro-magnetic device to allow the reverse sideways movement of the bar of points by spring means. Conveniently adjustable stop means are provided to control the extent of displacement of the bar of points.

The electro-magnetic device may be a solenoid operating from rest, or an electro-magnetic clutch having a continually moving part to which the bar of points is clutched and de-clutched.

The above and other features of the invention set out in the appended claims are incorporated in the construction which will now be described, as a speciiic embodiment with reference to the accompanying drawings in which:

FIGURE 1 is a cross sectional view of relevant parts of a Cottons patent straight bar knitting machine having latch opening means according to the invention.

FIGURE 2 is a plan View of part of FIGURE l.

FIGURE 3 is an enlarged cross sectional view of the machine needle bar and the bar of points.

FIGURE 4 is a simil-ar view to FIGURE 3 with the points engaged under the needle latches.

FIGURE 5 is a similar view to FIGURES 3 and 4 with the latches opened.

FIGURE 6 is a detail plan view of the machine needles and points.

FIGURE 7 is a similar view to FIGURE 6 showing the points engaged with the needles.

FIGURE 8 is a similar View to FIGURE 1 showing a modified arrangement.

FIGURE 9 is a similar view to FIGURE 2 showing the modified arrangement.

FIGURE 10 is a detail view of linkage in the modified arrangement.

FIGURE 11 is a detail sectional view of a clutch part of the modified arrangement.

Referring now to FIGURE l the machine is subst-antially as disclosed in said patent, to which reference is directed for full details, except that the machine needles are latch needles instead of being bearded needles, so that the machine is capable of automatically changing between the production of plain and rib fabric in the manner fully disclosed in said patent.

As hereinbefore referred to it is necessary when changing from plain to rib fabric to ensure that the latches of all machine needles are open ready for receiving new yarn for the iirst rib course.

This new yarn is actually fed to raised frame needles and onto the sinkers at a time when the machine needles are covered by the advanced sinkers and it is therefore necessary to provide a bar of latch opening points operable to open the machine needle latches before the sinkers are advanced to receive the new yarn.

FIGURE 1 shows the sinkers S in the retracted position and the machine latch needle 1 on the machine needle bar 2, with a bar 3 having latch opening points 4 disposed above the bar of needles.

The points 4 are formed at their free ends with catches 5 as shown in FIGURES 2, 6 and 7, by bending over the point ends at right angles to the stems.

The needle bar 2 is operated by the usual cam operated mechanism including horizontal arms 6, FIGURE l or 2 connecting the needle bar 2 to a spindle 7 and vertical arms S connecting spindle 7 to an operating shaft 9 which is rocked by a cam follower lever 9a having a cam follower 9b engaging a cam 9c on the main cam shaft 1t).

On each arm 6 there is mounted a bracket 11 which at its upper end provides an inclined slideway 12.

The bar 3 of points 4 has an advancing and retracting motion as guided by the slideways 12 for which purpose arms 13 are connected to the bar 3 and they carry rollers 14 which engage in the slideways 12, there being adjustable stops 15 carried by the brackets 11 and engaging the arms 13 to control the extent of advance.

For advancing and retracting the bar 3, the arms 13 are connected by links 16 to arms 17a which in one instance is one end of a bell crank lever 17 the other end of which is connected by a link 18 to a cam follower lever 19 having a cam follower 20 engaging a cam 21 on the main cam shaft 10, with a spring 22 on the lever 19 biasing the cam follower 21B onto the cam 21, and a spring 1711 biases the bell crank 17.

There is also a timing control device comprising a control disc 23 on the bottom disc control shaft 24 and having a control bit 25 for engaging one end 26a of a control lever 26 mounted on a rod 27 and the other end 26h of which is a hook for releasable engagement with a peg 28 projecting laterally from the lever 19.

In addition one of the arms 13 carrying the bar 3 of points 4 has a projection 13a for engaging and operating micro-switches 29, 30 when fully advanced and fully retracted respectively.

These micro-switches 29, 3i) are connected in suitable electric circuit with a solenoid 31.

This solenoid is carried by the spindle 7, and its core 31a is connected by -a spring 32 to a bracket 33 mounted on the bar 3 of points.

There is also a return spring 34 connected to the machine needle bar 2 and by a bracket 35 to the bar 3 of points.

Adjusting stop screws 36 are carried by the arms 13 and they co-operate with the brackets 11 to control the extent of sideways displacement of the bar 3 of points by the solenoid 31 through the springs 4and micro-switches.

FIGURE 3 shows the inoperative retracted position of the bar 3 of points 4 in relation to the machine needle bar 2, the points 4 being spaced upwardly and rearwardly from the machine needles 1 and the bent over catches S projecting in one sideways direction from the stems of the points.

FIGURE 4 shows the advanced operative position of the bar 3 of points in which the catches 5 of the points 4 are disposed immediately `adjacent one side of the latch ends of the needles for which purpose the catches 5 are sufficiently short to allow their insertion between successive needles as shown in FIGURE 6.

This advancing movement of the bar 3 of points 1s effected by a fall part 21a of the cam 21 acting on the cam -follower lever 19, and the mechanism connecting it to the bar 3, and the fall part 21a acting at a stage when the control bit 2S on the control disc 23 has released the control lever 26 for the latter to move by a spring 26C connected toit to release its hook 26h `from the peg 28 thereby allowing the movement of the cam follower lever 19.

The operation of the cam disc 23 is timed for its release operation to take place at the required time before the draw for the irst course of rib fabric and while the sinkers S are retracted.

The advance of the bars 3 of points terminates in the projection 13a on the arm 13 operating the micro-switch 29 thereby to energize the solenoid 31 which operates to displace the bar 3 of points sideways in the direction in which the catches 5 project from the points 4 so that these Catches 5 engage in the needle hooks under the needle latches as shown in FIGURE 4 and diagrammatically illustrated in FIGURE 7.

Following this stage a rise 21h on the cam 21 acts on the cam follower lever 19 to retract the bar 3 of points so that the catches 5 exert a pull on the needle latches to open them with a positive motion as shown in FIGURE 5. During this time a relay in the solenoid circuit retains the solenoid in its energized state thus keeping the points in their sideways operative position.

When the bar 3 of points is fully retracted the projection 13a on one of the arms 13 operates the microswitch 39 thereby to de-energize the solenoid 31 so that the bar 3 of points is displaced in the reverse sideways movement to its original position.

At this stage the control disc 23 is operated for the control bit 2S to re-engage the hook 26b of the control lever 26 with the peg 28 on the cam follower lever 19 whereby the latter and consequently the bar 3 of points is held inoperative until again required whenever there is a change from plain to rib fabric.

In a modied arrangement, the solenoid 31, springs 32, 34 and brackets 33, 35 are dispensed with. Instead there is an electro-magnetic clutch 37, FIGURES 8, 9 and l1, which is operated by the micro-switches 29, 30.

This clutch 37 is arranged for its operation to effect the sideways displacements of the point bar 3 by means as follows.

The point bar 3 has a bracket 38, FIGURES 8, 9, carrying a peg 39 engaging in a -fork arm 40 on a rod 41. This rod 41 is endwise slidable in brackets 42, 43 on the aforesaid rod 7 against action of a spring 44 between the bracket 43 and a collar 43 on the rod 41. For sliding the rod 41 it has a depending arm 46 connected by a link 47 to an arm 48 depending from an axle 49 of the clutch 37. This clutch axle 49 is mounted in bracket bearings 50, S1 secured to the machines, template rail 52.

The clutch may be of the type known as the Warner electro-magnetic clutch comprising a hub 53, FIGURE 1l, free on the axle 49 and which carries a field coil 54 having leads 55, 56 and a power supply terminal 57, and a hub S8 slidably mounted on the axle 59 by key 59 and keyway `601. This hub 58 carries an armature 61 through the intermediary of stub axles 62, 63 slidable in the hub 58 and mounting biasing springs 64, 65, 66, 67.

The hub 53 is oscillated, while the main cam shaft is rotating, through the intermediary of a cam 68 on the main cam shaft 111 operating a cam follower lever 69 connected by a link 711, FIGURE 10, to a lug 53a on the hub 53, there being also an adjustable limit stop 71 on an arm 72 on the axle 49 co-operating with a fixed stop part 73, FIGURE 8, of the bearing bracket S1.

It will thus be seen that when the micro-switches 29, 3@ are operated to energize the clutch 37, the hub 53 will be in motion from the cam 68, and the consequent immediate clutching of the coil 54 to the armature 61 results in immediate rotational movement of the hub 58 and consequently sideways movement of the point bar 3 in a desirably more spontaneous manner than for the solenoid operation which is necessarily from rest.

What we claim is:

1. A straight bar knitting machine having machine latch needles and latch opening means comprising a bar of points having their free ends in the form of catches, means for advancing the bar of points to carry the catches to locations at a side of the latch ends of the machine needles, means for displacing the bar of points in one sideways direction when advanced to engage their catch ends under the needle latches, means for then retracting the bar of points carrying the catches which open the latches, and means for displacing the bar of points in the reverse sideways direction following retraction.

2. A machine according to claim l wherein to provide the catches on the points the pointed ends are bent over at right angles to the stems of the points.

3. A machine according to claim 1 wherein the bar of points is operatively connected to mechanism -for advancing the machine needles.

4. A machine according to claim 1 wherein the bar of points is advanced and retracted by cam operated mechanism, an electric switch is operated at the end of the advance motion, an electro-magnetic device is energized by operation of the switch to effect the one sideways displacement of the bar of points, and when the bar of points is retracted, a second electric switch is operated which releases the electro-magnetic device to allow the reverse sideways movement of the bar of points by spring means.

5. A machine according to claim 1 wherein adjustable stop means are provided to control the extent of displacement of the bar of points.

6. A machine according to claim 1 wherein the electromagnetic device is a solenoid operating from rest.

7. A machine according to claim 1 wherein the electromagnetic device is an electro-magnetic clutch having a continually moving part to which the bar of points is clutched and de-clutched.

8. A straight bar knitting machine having a machine needle bar of latch needles, cam operated means operably connected to the machine needle bar including a lateraly movable rod and spaced arms connecting the machine needle bar to the rod, brackets on said arms formed with inclined slideways and one of which mounts spaced electric switches, slides mounted in said slideways and one of which has a projection for striking said electric switches, a point bar carried by said slides and having a row of points with bent over tips for releasable engagement with the machine needle latches, arms 0n said rod connected to said slides and movable by cam operated means rotatably displacing said rod to advance and retract the slides and consequently the point bar and said projection for operating said electric switches, a bracket attached to the point bar and connected by a spring to a solenoid carried from said rod, and said solenoid being electrically connected to said switches so that the solenoid upon being operated by the switches effects sideways movements of said points.

9. A straight bar knitting machine having a machine needle bar of latch needles, cam operated means operably connected to the machine needle bar including a laterally movable rod and spaced arms connecting the machine needle bar to the rod, brackets on said arms formed with inclined slideways and one of which mounts spaced electric switches, slides mounted in said slideways and one of which has a projection for striking said electric switches, a point bar carried by said slides and having a row of points with bent over tips for releasable engagement with the ,machine needle latches, arms on said `rod connected to said slides and movable by cam operated means rotatably displacing said rod to advance and retract the slides and consequently the point bar and said projection for operating said electric switches, a bracket attached to said point bar and connected to an endwise movable rod parallel to the point bar, an electromagnetic clutch the axle of which is connected by rocking arms and a link to said endwise movable rod, a irst clutch part of said clutch being connected slidably to said axle, and a second clutch part of which is free on said axle, cam operated means -for oscillating said second part of the clutch, and said clutch being electrically connected to said electric switches, so that the clutch upon being operated by the electric switches effects sideways movements of said points.

References Sites! UNITED STATES PATENTS 2,957,324 10/ 1960 Willuer 66-88 XR 3,129,572 4/1964 Werner 66-111 FOREIGN PATENTS 1,232,275 10/1960 France.

ROBERT R. MACKEY, Acting Primary Examiner. 

